The present invention relates to a percutaneous ostomy implant and a surgical method, which may use that implant, for creating a continent reservoir in communication with a percutaneous port.
Ileostomy and colostomy are common operations which may be necessitated, for example, by malignancy or chronic bowel inflammation. The surgery is called an ileostomy if the colon and rectum are removed and a colostomy if the rectum alone is removed. In these operations, a stoma is formed in the abdominal wall to which the ileum or colon respectively is connected. The stoma in most cases has to be connected to a bag.
However, instead of a conventional ileostomy, it is possible to make a reservoir known as a “Kock pouch” from the distal part of the ileum. It is formed in such a way that nipple valve is created which serves to close the reservoir, whilst allowing it to be drained intermittently by means of a catheter.
This is an example of a so-called continent ileostomy (CI); it was formerly an attractive alternative to conventional ileostomy, but is now rarely used. The complexity of the procedure and the high potential for complications—most of them related to dysfunction of the continence nipple valve—has deterred many surgeons from adopting the operation today. FIG. 1 illustrates (a) a conventional ileostomy and (b) a Kock's pouch ileostomy.
The advantages and drawbacks of the Kock pouch are discussed in Wasmuth, H. H., M. Svinsas, et al. (2007). “Surgical load and long-term outcome for patients with Kock continent ileostomy.” Colorectal Dis 9(8): 713-7; Olof Jonsson, Gunnar Olofsson, Elisabet Lindholm, Harriet Törnqvist, “Long-Time Experience with the Kock Ileal Reservoir for Continent Urinary Diversion”, Reconstructive Urology, Eur Urol 2001; 40:632-640; and Olof Jonsson, Bo Rangert, Frank Aldenborg, Magnus Campanello, Gunnar Wikholm and Staffan Akerlund, “Stabilization of the Nipple Base with Titanium Rings when Reoperating Patients with Continent Urostomies for Nipple Dysfunction”, Scand J Urol Nephro 30: 51-56, 1996.
The ileopouch anal anastomosis (IPAA) is today the gold standard worldwide for these patients, but as with a CI, this operation is also risky and failures are common, mostly leading to pouch excision with loss of bowel. Conversion of a failed IPAA to a CI would be a preferable option but again, surgeons are again reluctant to perform this complex and unreliable technique.
In their earlier patent application EP 1632201-A1, the present applicants disclosed a percutaneous ostomy implant comprising a solid-walled cylindrical body and an anchoring section in the form of a circular flange. The device was designed to be implanted through the abdominal wall and secured by the anchoring section which was located below the muscle layer. This section comprised inner and outer concentric rings interconnected by S-shaped members in order to provide an axially resilient structure which could absorb shear stresses and consequently reduce the risk of tissue damage. Spaces around the S-shaped members and provision of numerous apertures in the rings allowed for tissue ingrowth and vascularisation. It was proposed to connect the device to the side of the vessel (colon etc.) wall and by providing a removable lid a continent ostomy could be provided.
A development of this implant was disclosed in WO 2007/099500 in which the single solid-walled cylindrical body of EP 1632201-A1 was replaced by an outer skin-penetrating ring-like part spaced from the anchoring section by circumferentially-spaced legs. This implant was designed to receive a vessel drawn up through it; the spaces between the legs allowed the generation of a tissue bond between the inner part of the abdominal wall and the serosal tissue of the bowel in order to provide a more secure, stable, leak-proof and well-vascularised skin-implant junction. In some embodiments, a circumferential ingrowth mesh was additionally provided. This extended along most of the length of the cylindrical body with an annular gap being provided between it and the outer ring-like part to allow tissue to grow through the mesh within the outer ring-like part.
In a further development, in WO 2009/024568, the present applicants proposed a cylindrical body formed of two axially-spaced tubular parts. The outer tubular part penetrated the skin and was provided with means for connection to a bag or lid. The inner tubular part was attached to an anchoring flange of the type previously described. The two parts were connected together by a “distance means” comprising either radially-spaced legs or a rigid cylindrical ingrowth mesh which allowed for the generation of a tissue bond between the abdominal wall and the bowel. By means of this arrangement, a break was provided in the possible infection path along the implant from the skin. Furthermore, the outer tubular part penetrated the skin surface thereby isolating the skin surface—where sources of infection may be present—from the bowel tissue.